Method of drawing hollow glass articles.



F. L. BISHOP.

METHOD OF DRAWING HOLLOW GLASS ARTICLES.

APPLICATION FILED MAY13, 1914.

1,142,139, Pat ent ed lune 8, 1915.

WITN ESSES INVENTOR ,sra'rns rafranr caries.

FRETDERIO L. BISHOP, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WINDOW GLASS vention.

' MACHINE COMPANY,

JERSEY.

intense.-

and State of Pennsylvania, have invented a new and useful Method of Drawing Hollow Glass Articles, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing, forming part of this specification, in which the figure is an elevation, more or less conventional, illustrating the method of my in- My invention has relation to the drawing of hollow glass articles in accordance with the well known Lubbers'process, in which a hollow bait or blow-pipe is. lowered into a .bath of molten glass and then drawn up wardly with'the glass adhering thereto, air being admitted to the interior of the article during the drawing operation. This process is generally described in the Lubb'ers Patent No. 702,014 ofJune 10, 1902.;In the practice of this method it' was found necessary to provide the blow-pipe or bait with a constan'tly open small air outlet for the purpose of equalizing'the pressure in the article being. drawn and keep it substantially uniform. It was found that this vent was necessary by reason of the expansion and contraction of the air within the article durof the cylinder .35

til

ing the drawing operation, and which resulted in a breathing or pulsating action This vent opening is de-. scribed and claimed in the Lubbers Patent hid-886,618 of May 5, 1908. I have now discovered that the same automatic'regulating action may be obtained by forming the vent opening in the wall of the article itself, instead of in the blow-pipe or bait.

In accordance with my invention, after the drawing operation is started, and preferably after the usual neck and cap portion of the article have been formed, I make one or more small perforations through the glass wall of the article in the neck or cap por tion. This acts as the automatic vent or regulator during the remainder of the draw. v The perforation may be formed in any mannor of per orating glass known to the art, as

V by a suitable punching tool, blow-torch, etc.

By forming this perforation in the neck or cap portion of the article, the vent is provided during all portions of the drawing in which it .is necessary, and, furthermore, is

Specification of Letters Patent.

more uniform pressure. This OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF NEW METHOD OF DRAWING HOLLOW GLASS ARTICLES.

Batented June-8, 1915.

Application filed May 13, 1914. Serial No. 838,203.

formed in a part of the article which is always out off. in the operation of capping. ed the drawn article, so that no loss of glass. is occasioned thereby. I may, however, form this perforation at any desired point in the wall of the article. If desired, two or more perforations may be formed through the wall of the article being drawn at different levels, as at 2 and 3 in the accompanying drawing.

My invention obviatesthe. necessity of providing the blow-pipe or baits with special vent openings, as well as the necessity for more or less careful attendance on the part of the operator to see that these openings are kept free and unobstructed. The perforation or perforationsin the article it-.

self can be made by the blower or other attendant of the proper size to suit the particular character of article being drawn in each case, as to wall thickness, etc., as well as to suit the difi'erent conditions and kinds of glass. By puttingthe vent in' the article itself, I also obtain a better circulation of and outgoing air and consequently gives a gives a greater uniformity in the size. and wall.

thickness of the article being drawn.

I claim: 1. The method of drawing hollow glass 'articles, which consists in immersing a bait in a bath of molten glass and drawing the article therefrom, supplying gaseous fluid to g the interior of the article during the drawing operation, and forming a vent opening in the wall of said article to allow a portion of-such fluid to escape through such opening during the drawing operation, substantially as described. I

2. The method of drawing hollow glass articles, which consists in immersing a bait in a bath of molten glass and drawing the article therefrom, supplying gaseous fluid to the interior of the article during the drawing operation, and forming a plurality of .vent openings in the wallof said article at different levels to allow a portion of such fluid to escape through such openings during the drawing operation, substantially as described.

3. The 5 method of drawing hollow glass i article therefrom,,supplying gaseous fluid to the interior of the article during the drawing operation, and forming a 'vent opening in the Well of said article during the initial portion of the drawing operation to allowe portion of such fluid to escape through such opening during the remainder of the (ll-awin}: operation, substantially as described. In testimony whereof, I have hereunto set my hand.:

- FREDERIC L. BISHOP. Witnesses:

GEO. H. PARMELEE, H. MyCo'nwxN. 

